What are the commonly used materials in printing and packaging?

　　With the current surge in cultural demand, the printing industry is steadily advancing and growing.

　　China's total output value of the printing industry has risen to third place globally, with the digital printing sector steadily advancing. From basic typewritten copies to today's rapid growth in digital printing, this transformation has been driven by the continuous evolution of digital printing technology. As people increasingly rely on digital printing, the market prospects for this industry are virtually limitless.

　　With rising consumer standards, businesses today are increasingly focusing not only on product packaging but also on safety, environmental friendliness, and aesthetic design. But having seen so many packages, do you know what materials are commonly used for packaging?

　　I. Paper Packaging Materials

　　Throughout the evolution of packaging design, paper-based packaging materials—being a widely used and versatile option—have been extensively integrated into both manufacturing and everyday life. Paper is cost-effective, ideal for large-scale, mechanized production, and boasts excellent formability and foldability, making it perfect for high-quality printing. Additionally, it offers significant advantages such as recyclability, reusability, and its inherently eco-friendly, sustainable nature.

　　1. Kraft paper

　　It boasts high tensile strength, tear resistance, high tear energy, and excellent dynamic strength. The material is durable yet affordable, offering superior fold resistance and water repellency. It is commonly available as roll paper, though flat-sheet versions are also produced. Varieties include single-coat, double-coat, striped, and plain options, with colors ranging from white to yellowish-brown. Primarily used for packaging papers, envelopes, shopping bags, cement sacks, and even food packaging materials, this versatile paper finds applications across a wide range of industries.

　　2. Coated Paper

　　Coated paper, also known as printing coated paper, is primarily made from high-quality raw materials such as wood and cotton fibers. Its surface undergoes a coating and glossing process to enhance smoothness and shine, and it comes in both single-sided and double-sided varieties. Additionally, the paper surface is available in two finishes: glossy and textured. Coated paper boasts a smooth, pristine white appearance with excellent ink absorption and adhesion properties. It effectively reflects all colors in the light spectrum, delivering superior print quality, while maintaining minimal shrinkage or expansion.

　　Not only that, but it also comes in varieties such as single-coated (glossy on one side), double-coated, and matte-coated copper paper (matte-coated paper is known as "matt art paper" and is more expensive than regular coated paper). Commonly used weights include 80g, 105g, 115g, 128g, 157g, 180g, 200g, and 250g. This type of paper is ideal for color printing, particularly suited for offset and gravure printing of fine-line products like high-end photo albums, calendars, and illustrations found in books and magazines. After printing, the colors remain vibrant, with rich tonal variations and deep contrasts.

　　3. Whiteboard paper

　　Whiteboard paper is a type of cardboard with a white, smooth surface on the front and a predominantly gray back, commonly used for single-sided color printing to create paper boxes for packaging purposes.

　　It has a firm, thick texture with excellent stiffness, surface strength, fold resistance, and printability, making it ideal for applications such as packaging boxes, lining boards, and handmade crafts.

　　4. Corrugated Paper

　　Corrugated paper boasts advantages such as being lightweight yet sturdy, highly resistant to weight and compression, excellent at shock absorption, and moisture-proof—all while remaining cost-effective. Single-wall corrugated cardboard is typically used as a protective lining layer in product packaging or for crafting lightweight crates and pallets that safeguard goods from vibrations or impacts during storage and transportation. Three- or five-ply corrugated boards are ideal for creating sales packaging, whereas seven- or eleven-ply boards are primarily employed to manufacture sturdy packaging boxes designed for heavy-duty items like electrical machinery, furniture, motorcycles, and large household appliances. Corrugated paper is categorized into seven types based on its fluting pattern: A-flute, B-flute, C-flute, D-flute, E-flute, F-flute, and G-flute. Among these, A, B, and C-flutes are commonly used for outer packaging, while D and E-flutes are typically suited for medium- to small-sized packaging applications.

　　5. Gold and Silver Cardstock

　　To highlight the premium quality of printed packaging products, more and more customers are choosing to print with gold and silver cardstock. Based on years of printing experience, here’s a summary of key considerations when working with gold and silver cardstock in the printing process:

　　Gold and silver cardstock is a special type of paper that, unlike regular paper, comes in two varieties: glossy gold and matte gold, as well as glossy silver and matte silver. It’s created by laminating a thin layer of metallic foil—either gold or silver—onto a base of single-coated art paper or grey board. Because this material doesn’t readily absorb ink during printing, it requires the use of a fast-drying ink to ensure optimal results.

　　II. Plastic Packaging Materials

　　Packaging materials used for a wide variety of products are typically designed for single-use only. Once the product moves from the manufacturer to the consumer—or after the packaging is opened and the product is used—the material has fulfilled its purpose and is then collected as waste for recycling or disposal.

　　Therefore, when it comes to packaging materials, first, they must perform well and effectively meet the needs of protecting and promoting the product. Second, their cost should be kept as low as possible. Today, among plastics, so-called "general-purpose" plastics like polyethylene and polypropylene stand out as the preferred materials for plastic packaging due to their excellent performance, large-scale production capabilities, and affordability.

　　Plastics boast excellent water resistance, moisture protection, oil resistance, and electrical insulation, while also being lightweight, easily colorable, and simple to manufacture. They can be molded into a wide variety of shapes, making them ideal for printing applications. Moreover, their raw materials are abundant, inexpensive, and deliver superior performance, making plastics one of the most important packaging materials in modern retail packaging.

　　Common packaging plastic materials primarily include polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and polyethylene terephthalate (PET).

　　3. Metal Packaging Materials

　　Metals are widely used in industrial product packaging, transportation packaging, and sales packaging. They boast excellent mechanical properties and barrier performance, offering superior all-around protection, along with an attractive appearance, easy processing capabilities, abundant resources, and favorable waste-disposal characteristics. With their sleek, metallic sheen and ease of printing and decoration, metals are extensively employed in food packaging, pharmaceutical packaging, daily-use product packaging, instrument and equipment packaging, industrial goods packaging, and even military ammunition packaging—particularly in large quantities for food-related applications.

　　1. Steel Material Packaging

　　Compared to other metal packaging materials, steel is more abundant in supply, cheaper in price, and requires lower energy consumption and costs. It also boasts excellent formability and ductility. As a result, steel accounts for the largest share of usage among metal packaging materials.

　　2. Aluminum Packaging

　　Aluminum is lightweight, boasts excellent machinability, and offers superior ductility and corrosion resistance—making it highly resistant to rust. It maintains a bright, attractive finish that lasts over time, while also being easy to print on, process, and recycle. Primarily used in sales packaging—such as the ubiquitous beverage cans—aluminum comes in various forms, including pure aluminum sheets, alloy aluminum sheets, aluminum foil, and aluminized films. Notably, aluminum exhibits strong corrosion resistance, even outperforming stainless steel in certain applications. For instance, when used for seafood packaging, aluminum prevents the unsightly blackening caused by metal sulfide formation from sulfur compounds found in proteins.

　　4. Glass and Ceramic Packaging Materials

　　Glass boasts high transparency, impermeability, and corrosion resistance, is non-toxic and odorless, exhibits stable chemical properties, and can be produced at relatively low costs—making it ideal for crafting transparent and translucent containers in a wide variety of shapes and colors. Ceramics, on the other hand, offer excellent chemical and thermal stability, resisting erosion from a broad range of chemicals and enduring high temperatures without degrading. Even rapid temperature changes—whether from extreme heat or cold—have no adverse effect on ceramic materials, which makes them perfect for use as packaging containers for food and chemicals. Both glass and ceramics belong to the silicate family of materials. Glass and ceramic packaging refers specifically to containers made from either ordinary or specialized types of glass and ceramics, such as glass bottles, glass jars, ceramic bottles, jars, vats, pots, and pitchers.